package cn.kgc.zuxin.controller;

import cn.kgc.zuxin.common.R;
import lombok.extern.slf4j.Slf4j;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;
import org.springframework.web.multipart.MultipartFile;

import javax.servlet.ServletOutputStream;
import javax.servlet.http.HttpServletResponse;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.lang.reflect.Field;
import java.util.UUID;
import java.util.WeakHashMap;

/**
 * 文件上传和下载
 *
 * @author : 磊
 * Creat Date : 2022/10/27 9:31
 */
@Slf4j
@RestController
@RequestMapping("/common")
public class CommonController {
    @Value("${ZX.path}")
    private String basePath;

    /**
     * 文件上传
     *
     * @param file
     * @return 上传结果
     */
    @PostMapping("/upload")
    public R<String> upload(MultipartFile file) {
        //file是一个临时文件,需要转存到其他位置,否则本次请求完成后,临时文件会删除
        log.info(file.toString());

        //原始文件名
        String originalFilename = file.getOriginalFilename();
        String substring = originalFilename.substring(originalFilename.lastIndexOf("."));
        //使用UUID重新生成文件名,防止文件名重复导致被覆盖
        String fileName = UUID.randomUUID().toString() + substring;
        //创建一个目录对象
        File file1 = new File(basePath);
        //判断当前目录是否存在
        if (!file1.exists()) {
            //目录不存在需要创建
            file1.mkdirs();
        }

        try {
            //将临时文件转存到指定位置
            file.transferTo(new File(basePath + fileName));
        } catch (IOException e) {
            e.printStackTrace();
        }
        return R.success(fileName);
    }

    /**
     * 文件下载
     *
     * @param name
     * @param response
     */
    @GetMapping("/download")
    public void download(String name, HttpServletResponse response) {
        //输入流,通过输入流读取文件
        try {
            FileInputStream fileInputStream = new FileInputStream(new File(basePath + name));
            //输出流,通过输出流将文件写回
            ServletOutputStream outputStream = response.getOutputStream();

            response.setContentType("image/jpeg");

            int len = 0;

            byte[] bytes = new byte[1024];

            while ((len = fileInputStream.read(bytes)) != -1) {

                outputStream.write(bytes, 0, len);

                outputStream.flush();
            }
            //关闭流
            outputStream.close();
            fileInputStream.close();
        } catch (IOException e) {
            e.printStackTrace();
        }

    }
}
